Although, it get worse, because he has only 5 supplies and who knows what size or how they are run. Plus, we just found out they are in the floor. That's the worst place to try and A/C a 2nd floor. I would like to see at least 2tons to that area.
You can add return to the 2nd floor all day long and not make a difference if there is not enough supply. Again, assuming there is enough RA to the system now. And I would not take that bet.